diff --git a/wasm-port/docs/compatibility-validation.md b/wasm-port/docs/compatibility-validation.md
index e3827cb..6c05fd7 100644
--- a/wasm-port/docs/compatibility-validation.md
+++ b/wasm-port/docs/compatibility-validation.md
@@ -24,6 +24,12 @@ The current OPFS host-boundary validation command is:
 wasm-port/tests/opfs/node/verify_file_service.sh
 ```
 
+The current browser smoke validation command is:
+
+```bash
+wasm-port/tests/browser/verify_ini_panel_browser.sh
+```
+
 ## Validation Chain
 
 The native validation script runs these checks in order:
@@ -57,6 +63,11 @@ with a Node mock of the browser File System Access handles. It covers nested
 directory creation, text save/load, missing file behavior, invalid relative
 paths, and unavailable OPFS storage.
 
+The browser smoke script serves `wasm-port/` over localhost and runs Chromium
+headless against a test page that imports the JS SDK, loads the INI WASM
+module, queries vendored LinuxCNC INI parsing through the SDK, and performs an
+OPFS text-file round trip.
+
 ## Source Coverage
 
 Every `.c` and `.cc` entry in `tools/source-manifest.txt` must have a
@@ -105,6 +116,7 @@ The validation fails if:
 | --- | --- |
 | `tests/wasm/node/verify_ini_wasm.sh` | Validates the browser-facing INI WASM module can be built from vendored LinuxCNC `inifile.cc`, loaded through the JS SDK in Node, and queried through the exported C ABI. |
 | `tests/opfs/node/verify_file_service.sh` | Validates the host-owned OPFS text-file adapter used by the browser INI panel without moving file persistence into the WASM core. |
+| `tests/browser/verify_ini_panel_browser.sh` | Validates the INI SDK, WASM module loading, and OPFS text-file round trip in a real browser runtime. |
 
 ## Fixture Coverage
 
@@ -149,8 +161,9 @@ Negative fixtures currently cover:
 
 Current full-core validation is native-only. WASM/SDK validation is limited to
 the INI parser smoke harness. OPFS validation is limited to the JavaScript
-host-boundary adapter. Browser-level validation, full SDK coverage, and full
-machine-session validation remain future work.
+host-boundary adapter plus the INI browser smoke harness. Full browser
+coverage, full SDK coverage, and full machine-session validation remain future
+work.
 
 The current fixture expectations validate standalone behavior against both the
 vendored LinuxCNC source path and an upstream `rs274` side-by-side baseline for
diff --git a/wasm-port/docs/drift-report.md b/wasm-port/docs/drift-report.md
index 0acd558..1adbafb 100644
--- a/wasm-port/docs/drift-report.md
+++ b/wasm-port/docs/drift-report.md
@@ -56,12 +56,12 @@ semantic rewrites:
 
 ## Known Gaps
 
-- No browser/full-core WASM parity tests yet. The INI parser now has a Node
-  WASM smoke harness against vendored LinuxCNC `inifile.cc`.
+- No browser/full-core WASM parity tests yet. The INI parser now has Node and
+  Chromium smoke harnesses against vendored LinuxCNC `inifile.cc`.
 - JS SDK validation is currently limited to the INI WASM wrapper around
   vendored LinuxCNC `inifile.cc`.
-- OPFS validation is currently limited to a Node mock of the browser
-  file-service adapter; browser-level OPFS validation is not yet established.
+- OPFS validation covers a Node mock of the file-service adapter and a
+  Chromium localhost round trip for INI text-file persistence.
 - Identity/trivial, `5axiskins`, TRT `xyzac`/`xyzbc`, delta, SCARA, PUMA,
   serial, hexapod, pentapod, and related kinematics sources now have native
   source-probe coverage.
diff --git a/wasm-port/docs/source-reuse-map.md b/wasm-port/docs/source-reuse-map.md
index 611db22..9879781 100644
--- a/wasm-port/docs/source-reuse-map.md
+++ b/wasm-port/docs/source-reuse-map.md
@@ -31,7 +31,7 @@ Current validation is intentionally mechanical:
 
 | Capability | LinuxCNC source files | Port classification | Standalone boundary | Current validation |
 | --- | --- | --- | --- | --- |
-| INI parsing | `src/emc/ini/inifile.cc`, `inifile.h`, `inifile.hh` | Copy unchanged | Native file IO remains LinuxCNC-style in the vendored parser; browser OPFS integration remains outside this layer; `runtime/sdk/src/linuxcnc-ini.js` only wraps the exported WASM C ABI | Vendor byte sync, `linuxcnc_ini_probe`, `linuxcnc_inifile_source_probe`, `tests/wasm/node/verify_ini_wasm.sh` |
+| INI parsing | `src/emc/ini/inifile.cc`, `inifile.h`, `inifile.hh` | Copy unchanged | Native file IO remains LinuxCNC-style in the vendored parser; browser OPFS integration remains outside this layer; `runtime/sdk/src/linuxcnc-ini.js` only wraps the exported WASM C ABI | Vendor byte sync, `linuxcnc_ini_probe`, `linuxcnc_inifile_source_probe`, `tests/wasm/node/verify_ini_wasm.sh`, `tests/browser/verify_ini_panel_browser.sh` |
 | RTAPI compatibility headers | `src/rtapi/rtapi_*.h` in the manifest | Copy unchanged plus standalone shim include path | `runtime/core/shims/rtapi.h` supplies the minimal standalone RTAPI surface needed by vendored code | Vendor byte sync, compile coverage through dependent source probes |
 | Canon/NML-facing interpreter types | `src/emc/nml_intf/canon*.hh`, `emctool.h`, `interp_return.hh`, `motion_types.h`, `emcpose.*`, `emcpos.h`, `debugflags.h`, `src/emc/linuxcnc.h` | Copy unchanged plus narrow standalone status shim | NML transport is not ported; `runtime/core/shims/nml_intf/emc.hh` exposes only the `emcStatus` machine-units status edge currently needed by vendored interpreter conversion and initialization code | Vendor byte sync, dependent source probes, `linuxcnc_emc_status_probe`, `linuxcnc_tp_api_probe`, interpreter harnesses |
 | Motion state headers | `src/emc/motion/state_tag.h`, `emcmotcfg.h`, `simple_tp.h`, `motion.h`, `mot_priv.h`, `axis.h` | Copy unchanged | Realtime motion process is not ported; standalone probes seed the small motion status/config state required by TP calls | Vendor byte sync, `linuxcnc_tp_api_probe` |
@@ -70,8 +70,9 @@ Current validation is intentionally mechanical:
   fixture-covered through vendored `interp_convert.cc` and `interp_queue.cc`.
 - Browser/WASM C ABI and JS SDK layers are not yet built for the full
   interpreter/planner core. The INI parser has a minimal JS SDK wrapper and
-  Node WASM smoke harness.
+  Node/browser WASM smoke harnesses.
 - OPFS persistence is connected to the INI panel through the host-side
   `runtime/opfs/file-service.js` adapter; tool table, parameter file, G-code
-  program loading, and browser-level OPFS validation remain future work.
+  program loading, and broader browser-level OPFS validation remain future
+  work.
 - Native LinuxCNC GUI code remains out of scope for implementation.
diff --git a/wasm-port/tests/browser/ini_panel_smoke.html b/wasm-port/tests/browser/ini_panel_smoke.html
new file mode 100644
index 0000000..f1cd728
--- /dev/null
+++ b/wasm-port/tests/browser/ini_panel_smoke.html
@@ -0,0 +1,59 @@
+<!doctype html>
+<html lang="en">
+<head>
+  <meta charset="utf-8">
+  <title>LinuxCNC INI Browser Smoke</title>
+</head>
+<body>
+  <pre id="status">running</pre>
+  <script type="module">
+    import { createLinuxCncIniSdk } from "../../runtime/sdk/src/linuxcnc-ini.js";
+    import { loadTextFile, saveTextFile } from "../../runtime/opfs/file-service.js";
+
+    const status = document.getElementById("status");
+
+    function assertEqual(actual, expected, label) {
+      if (actual !== expected) {
+        throw new Error(`${label}: expected ${expected}, got ${actual}`);
+      }
+    }
+
+    try {
+      const ini = await createLinuxCncIniSdk();
+      const wasmPath = "/work/browser-smoke.ini";
+      const iniText = `[EMC]
+MACHINE = browser-smoke
+
+[TRAJ]
+LINEAR_UNITS = mm
+COORDINATES = X Y Z
+
+[KINS]
+KINEMATICS = trivkins
+JOINTS = 3
+`;
+
+      ini.writeTextFile(wasmPath, iniText);
+      assertEqual(ini.getString(wasmPath, "EMC", "MACHINE"), "browser-smoke", "machine");
+      assertEqual(ini.getString(wasmPath, "TRAJ", "LINEAR_UNITS"), "mm", "units");
+      assertEqual(ini.getString(wasmPath, "KINS", "KINEMATICS"), "trivkins", "kinematics");
+      assertEqual(ini.getString(wasmPath, "TRAJ", "MISSING"), null, "missing tag");
+
+      const fields = ini.getFields(wasmPath, {
+        machine: { section: "EMC", tag: "MACHINE" },
+        joints: { section: "KINS", tag: "JOINTS" },
+      });
+      assertEqual(fields.machine, "browser-smoke", "field machine");
+      assertEqual(fields.joints, "3", "field joints");
+
+      const opfsPath = "linuxcnc/browser-smoke.ini";
+      await saveTextFile(opfsPath, iniText);
+      assertEqual(await loadTextFile(opfsPath), iniText, "opfs roundtrip");
+
+      status.textContent = "browser_ini_opfs_smoke=ok";
+    } catch (error) {
+      status.textContent = `browser_ini_opfs_smoke=fail ${error.stack || error.message}`;
+    }
+  </script>
+</body>
+</html>
diff --git a/wasm-port/tests/browser/verify_ini_panel_browser.sh b/wasm-port/tests/browser/verify_ini_panel_browser.sh
new file mode 100755
index 0000000..0f19a62
--- /dev/null
+++ b/wasm-port/tests/browser/verify_ini_panel_browser.sh
@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "$0")/../.." && pwd)"
+CHROMIUM="${CHROMIUM:-$(command -v chromium || command -v chromium-browser || command -v google-chrome || command -v google-chrome-stable || true)}"
+
+if [[ -z "$CHROMIUM" ]]; then
+  echo "missing Chromium-compatible browser; set CHROMIUM=/path/to/browser" >&2
+  exit 1
+fi
+
+"$ROOT_DIR/tools/build_ini_panel.sh"
+
+TMP_DIR="$(mktemp -d)"
+PORT_FILE="$TMP_DIR/port"
+SERVER_LOG="$TMP_DIR/server.log"
+CHROME_PROFILE="$TMP_DIR/chrome-profile"
+mkdir -p "$CHROME_PROFILE"
+
+cleanup() {
+  if [[ -n "${SERVER_PID:-}" ]]; then
+    kill "$SERVER_PID" 2>/dev/null || true
+    wait "$SERVER_PID" 2>/dev/null || true
+  fi
+  rm -rf "$TMP_DIR"
+}
+trap cleanup EXIT
+
+python3 - <<'PY' "$ROOT_DIR" "$PORT_FILE" >"$SERVER_LOG" 2>&1 &
+import functools
+import http.server
+import pathlib
+import socketserver
+import sys
+
+root = pathlib.Path(sys.argv[1])
+port_file = pathlib.Path(sys.argv[2])
+
+handler = functools.partial(http.server.SimpleHTTPRequestHandler, directory=str(root))
+with socketserver.TCPServer(("127.0.0.1", 0), handler) as httpd:
+    port_file.write_text(str(httpd.server_address[1]), encoding="ascii")
+    httpd.serve_forever()
+PY
+SERVER_PID=$!
+
+for _ in $(seq 1 100); do
+  [[ -s "$PORT_FILE" ]] && break
+  sleep 0.05
+done
+
+if [[ ! -s "$PORT_FILE" ]]; then
+  echo "browser smoke HTTP server did not start" >&2
+  cat "$SERVER_LOG" >&2 || true
+  exit 1
+fi
+
+PORT="$(cat "$PORT_FILE")"
+URL="http://127.0.0.1:$PORT/tests/browser/ini_panel_smoke.html"
+OUT="$TMP_DIR/chromium.out"
+
+"$CHROMIUM" \
+  --headless=new \
+  --disable-gpu \
+  --no-sandbox \
+  --user-data-dir="$CHROME_PROFILE" \
+  --virtual-time-budget=10000 \
+  --dump-dom \
+  "$URL" >"$OUT" 2>&1
+
+if ! grep -Fq "browser_ini_opfs_smoke=ok" "$OUT"; then
+  echo "browser INI/OPFS smoke failed" >&2
+  sed -n '1,220p' "$OUT" >&2
+  exit 1
+fi
+
+echo "browser_ini_opfs_smoke=ok"